1. Field of the Invention
The present invention relates to an X-ray tube and an X-ray analyzing apparatus used for, for example, a fluorescent X-ray analyzing apparatus of an energy dispersion type and preferable for a small-sized and light-weighted handy type and portable type.
2. Description of the Related Art
Fluorescent X-ray analysis carries out a qualitative analysis or a quantitative analysis of a sample by irradiating primary X-ray emitted from an X-ray source to the sample and detecting fluorescent X-ray emitted from the sample by an X-ray detector to thereby acquire a spectrum from an energy of the fluorescent X-ray. The fluorescent X-ray analysis is widely used in step/quality control since the sample can be analyzed nondestructively and swiftly.
As analyzing methods of the fluorescent X-ray analysis, there are a wavelength dispersion type of measuring a wavelength and an intensity of an X-ray, an energy dispersion type of detecting the fluorescent X-ray by a semiconductor detecting element without dispersing the fluorescent X-ray and measuring an energy and an intensity of the X-ray by a pulse height analyzer.
In a related art, for example, Patent Reference 1 (JP-A-8-115694), in order to promote a sensitivity of fluorescent X-ray, a trial is carried out for making an X-ray tube and an X-ray analyzer proximate to a sample by providing the X-ray tube with a take out window for taking out fluorescent X-ray passing inside thereof to outside.
Further, as described in Patent Reference 2 (Japanese Patent No. 3062685), an energy dispersion type fluorescent X-ray analyzing apparatus of a handy type has been spread by small-sized formation of an X-ray tube and an X-ray analyzer.
According to the above-described related arts, the following problem remains.
For example, although according to the X-ray analyzing apparatus described in Patent Reference 1, there is achieved a significant effect promoting a detection sensitivity by making the X-ray tube and the X-ray detector proximate to the sample, the X-ray tube and the X-ray detector are respectively provided with limited and constant or more of sizes, and therefore, there is a limit in making the X-ray tube and the X-ray detector proximate to the sample.
Further, according to the handy type energy dispersion type fluorescent X-ray analyzing apparatus of the related art, although further small-sized formation and light-weighted formation are requested, as a constitution of the apparatus, the X-ray tube and the X-ray detector occupy most of a volume and a mass, and therefore, according to the related art, there is a limit in achieving further small-sized formation and light-weighted formation. Further, the handy type is constituted by an open type of irradiating primary X-ray directly to the sample in the atmosphere without containing the sample at inside of a sample chamber in a hermetically closed state to analyze, and therefore, in view of safety against X-ray, an amount of generating X-ray from the X-ray tube is restricted, and therefore, it is necessary to detect fluorescent X-ray from the sample further efficiently.